MA240026 Microchip Technology, MA240026 Datasheet - Page 200

• Manufacturer Part Number: MA240026
• Description: Daughter Cards & OEM Boards PIC24FJ16MC102 Plug-In Module
• Manufacturer: Microchip Technology

Specifications of MA240026

• Rohs: yes
• Data Bus Width: 16 bit
• Description/function: PIC24F 28 Pin QFN to 100 Pin Plug-in-Module
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 3 V to 3.6 V

PIC24FJ16MC101/102
21.1
The RTCC module registers are organized into three
categories:
• RTCC Control Registers
• RTCC Value Registers
• Alarm Value Registers
21.1.1
To limit the register interface, the RTCC Timer and
Alarm
corresponding register pointers. The RTCC Value
register window (RTCVALH and RTCVALL) uses the
RTCPTR bits (RCFGCAL<9:8>) to select the desired
timer register pair (see
By writing the RTCVALH byte, the RTCC Pointer value,
RTCPTR<1:0> bits, decrement by one until they reach
‘00’. Once they reach ‘00’, the MINUTES and
SECONDS value will be accessible through RTCVALH
and RTCVALL until the pointer value is manually
changed.
TABLE 21-1:
The Alarm Value register window (ALRMVALH and
ALRMVALL)
(ALCFGRPT<9:8>) to select the desired Alarm register
pair (see
EXAMPLE 21-1:
DS39997B-page 200
MOV
MOV
MOV
MOV
MOV
BSET
RTCPTR
<1:0>
00
01
10
11
Time
RTCC Module Registers
Table
#NVMKEY, W1
#0x55, W2
#0xAA, W3
W2, [W1]
W3, [W1]
RCFGCAL, #13
REGISTER MAPPING
21-2).
registers
uses
RTCVAL<15:8>
RTCVAL REGISTER MAPPING
RTCC Value Register Window
WEEKDAY
MINUTES
MONTH
SETTING THE RTCWREN BIT
Table
—
the
are
21-1).
;move the address of NVMKEY into W1
;start 55/AA sequence
;set the RTCWREN bit
accessed
ALRMPTR
RTCVAL<7:0>
SECONDS
HOURS
YEAR
DAY
through
Preliminary
bits
By writing the ALRMVALH byte, the Alarm Pointer
value, ALRMPTR<1:0> bits, decrement by one until
they reach ‘00’. Once they reach ‘00’, the ALRMMIN
and ALRMSEC value will be accessible through
ALRMVALH and ALRMVALL until the pointer value is
manually changed.
TABLE 21-2:
Considering that the 16-bit core does not distinguish
between 8-bit and 16-bit read operations, the user must
be aware that when reading either the ALRMVALH or
ALRMVALL bytes will decrement the ALRMPTR<1:0>
value. The same applies to the RTCVALH or RTCVALL
bytes with the RTCPTR<1:0> being decremented.
21.1.2
In order to perform a write to any of the RTCC Timer
registers, the RTCWREN bit (RCFGCAL<13>) must be
set (refer to
ALRMPTR
Note:
Note:
<1:0>
00
01
10
11
This only applies to read operations and
not write operations.
WRITE LOCK
To avoid accidental writes to the timer, it is
recommended that the RTCWREN bit
(RCFGCAL<13>) is kept clear at any
other time. For the RTCWREN bit to be
set, there is only 1 instruction cycle time
window allowed between the 55h/AA
sequence and the setting of RTCWREN;
therefore, it is recommended that code
follow the procedure in
Example
ALRMVAL<15:8> ALRMVAL<7:0>
ALRMVAL REGISTER
MAPPING
Alarm Value Register Window
ALRMMNTH
ALRMMIN
ALRMWD
21-1).
© 2011 Microchip Technology Inc.
—
Example
ALRMSEC
ALRMDAY
ALRMHR
—
21-1.